Halting and reversing upward secular trends in body weight in the US is an important medical and public health challenge. Additional skilled researchers in obesity prevention are much needed, but training programs are few. Obesity is a complex disorder that has multiple causes and multiple potential strategies for prevention and treatment. The present proposal is for a training grant called the Minnesota Obesity Prevention Training (MnOPT) program. Its goal is to provide multidisciplinary training for a new generation of obesity prevention scientists. The proposed training program would have three training tracks: basic science, behavioral epidemiology, and clinical. The MnOPT program will provide training for predoctoral, postdoctoral, and medical fellows. There will be 6 training slots: 3 predoctoral and 3 postdoctoral fellows. Robert Jeffery, professor in Epidemiology and Community Health, is the Program Director. Catherine Kotz, professor in the Department of Food Science and Nutrition, and Charles Billington, professor in Medicine, are the Codirectors. Dr. Billington will oversee the clinical science, Dr. Kotz the basic science, and Dr. Jeffery the behavioral epidemiology training. There are 36 participating faculty with active research programs who will serve as mentors in these areas. Trainees will be exposed to research and training in each of these fields. Trainees will complete a research projects, publish manuscripts, complete a core curriculum, attend journal clubs and seminars, and receive training in grant writing, research ethics and career development. The training arms will ensure that the diverse disciplines engaged in obesity research are well represented and there is cross-fostering between arms to fulfill the need for transdisciplinary training. The University of Minnesota and affiliated research facilities are uniquely qualified to host this training grant. As a large research university with Schools of Public Health, Medicine, Agriculture, NIH-supported Comprehensive Obesity and Obesity Prevention Centers, and a General Clinical Research Center, the University of Minnesota has the resources to provide trainees with a broad training experience in research ranging from basic mechanisms underlying obesity development to clinical and behavioral strategies to prevent obesity.